From false-alarm rate to alerts per engineer per day
A false-alarm rate is a statistic. An alert arriving on a phone at 03:00 is an event with a cost. This converts one into the other, and it is the arithmetic that ends more deployments than accuracy ever does.
Fleet alerts per day
–
false alarms only
Per engineer per day
–
every one must be looked at
Triage hours per engineer per day
–
before any real work
Events caught
–
what the fleet buys for that
The trade the room has to make
Each point is an operating point on the isolation forest. Left is a quiet system that misses failures; right is a system nobody reads.
Say the number out loud
A false-positive rate of half a percent sounds like a rounding error. Multiply it by the
fleet and the windows in a day, divide by the people who must action it, and it becomes a
staffing decision. Do this arithmetic in the first week of a project, not the last.
Computed by scripts/build_models.py in 86.4s at 2026-08-09T19:08:15+00:00 · scikit-learn 1.6.1 · seed 20260809 · source: MetroPT-3 (Air Production Unit of a Metro do Porto train), CC BY 4.0, DOI 10.24432/C5VW3R. Nothing on this page is hardcoded.